Proton pump inhibitors represented by omeprazole, which suppress gastric acid secretion for the treatment of peptic ulcer, reflux esophagitis and the like, have been widely used in clinical situations. However, the existing proton pump inhibitors are associated with problems in terms of effect and side effects. To be specific, since the existing proton pump inhibitors are unstable under acidic conditions, they are often formulated as enteric preparations, in which case several hours are required before onset of action, and about 5 days to exhibit maximum efficacy by consecutive administration. In addition, since the existing proton pump inhibitors show variable treatment effects due to metabolic enzyme polymorphism and drug interaction with medicaments such as diazepam and the like, an improvement has been desired.
As pyrrole compounds having a proton pump inhibitory action, patent reference 1 describes a compound represented by the formula:
wherein X and Y are the same or different and each is a bond or a spacer having 1 to 20 atoms in the main chain, r1 is an optionally substituted hydrocarbon group or an optionally substituted heterocyclic group, r2, r3 and r4 are the same or different and each is a hydrogen atom, an optionally substituted hydrocarbon group, an optionally substituted thienyl group, an optionally substituted benzo[b]thienyl group, an optionally substituted furyl group, an optionally substituted pyridyl group, an optionally substituted pyrazolyl group, an optionally substituted pyrimidinyl group, an acyl group, a halogen atom, a cyano group or a nitro group, and r5 and r6 are the same or different and each is a hydrogen atom or an optionally substituted hydrocarbon group. In addition, as a pyrrole compound having a proton pump inhibitory activity, patent document 2 describes a compound represented by the formula
wherein r7 is a monocyclic nitrogen-containing heterocyclic group optionally fused with a benzene ring or heterocycle, the monocyclic nitrogen-containing heterocyclic group optionally fused with a benzene ring or heterocycle optionally has substituent(s), r8 is an optionally substituted C6-14 aryl group, an optionally substituted thienyl group or an optionally substituted pyridyl group, r9 and r10 are the same or different and each is a hydrogen atom or one of r9 and r10 is a hydrogen atom and the other is an optionally substituted lower alkyl group, an acyl group, a halogen atom, a cyano group or a nitro group, and r11 is an alkyl group, and the like.
Furthermore, as a therapeutic drug for neoplastic diseases or autoimmune diseases, patent reference 3 describes a compound represented by the formula:
wherein r7 is aryl, aralkyl, heteroaryl or the like, r8 is aryl, heteroaryl or the like, and r9 is aryl, heteroaryl, optionally substituted aminomethyl or the like.Patent reference 1: WO 2006/036024Patent reference 2: WO 2007/026916Patent reference 3: WO 2004/103968